PHOTO: DAVID GRUBER. ART: MARC JOHNS
Science
EXPLORE
Sharks
Go With
the Glow
CATS DIG THEIR OWN KIND OF MUSIC
People who leave the radio on for their cat while they ’re out
aren’t doing Tabby a favor, a recent study suggests. Researchers
tracked how cats respond to music for humans versus music
composed with the high pitch of feline voices and the tempo
of purring or suckling. Cats mostly ignored classical works and
overwhelmingly responded to the tunes created for them, in
some cases even rubbing against the speaker. “ We’re trying to
get people to think more carefully about why they ’re playing
music,” says University of Wisconsin psychologist Charles
Snowdon, “and who it’s really benefiting.” —A . R. Williams
Marine biologist David Gruber specializes in finding life-forms that biofluoresce—
creatures whose uniquely structured skin absorbs undersea deep-blue light and
reemits it as neon green, red, or orange. Gruber, whose work is supported by
the National Geographic Society, has found biofluorescence in jellyfish, corals,
a sea turtle, and more than 200 fish and shark species. Now the diver-scientist
is expanding his research beyond how these fish look to explore how they see.
Gruber had a Cornell University eye specialist examine a “brilliantly fluorescent”
swell shark (above). Humans’ eyes see a broad spectrum of colors. This shark
“sees only in the blue-green range,” Gruber says, but in that range it sees acutely.
Armed with an underwater camera that mimics the shark’s vision, he hopes to
learn how biofluorescence helps the shark with camouflage, mating, and more.
Meanwhile, Gruber says, the shark’s-eye-view camera fosters “a sense of
empathy with these animals, to see how they see the world.”
—Patricia Edmonds
Gruber photographed this shark
with a biofluorescent camera
that casts a blue light, which the
shark’s skin reemits as green.